Don’t guess on your keywords. You can use various tools (Google Adwords work great!) to see which keywords have the least competition and the highest volume. Different goals require different types, for example, brand or geographical specific focuses should consider long-tail keyword phrases and local specific keywords. If you search for a specific keyword and see you have thousands or millions of competitors it might be better and easier to go with the long-tail keywords.
Have questions? Feel free to email us at erik [at] tropikmedia [dot] com